Electrical treater method



March 30, 1943. H. c. EDDY ELECTRICAL TREATER METHOD Filed Feb. 2a, 1938iii [/VVE/VTOQ HA ROAD C. EDDY 6 7 HA RR/s, K/ECH) FOJTER & HARR/J A7'7'OQNEYJ.

Patented Mar. 30, 1943 UNl'lED STATES/"- PATENT- OFF-ICE ELECTRICALTREATER METHOD Harold C. Eddy, Los Angeles, Calif., assignor, by mesneassignments, to Petrolite Corporation, Ltd, Wilmington, Del., acorporation of Delaware Application February 28, 1938, Serial No.192,957

10 Claims.

emulsions such ascrude oil emulsions by electrical treatment andsettling.

An emulsion or mixture havinga non-conducting liquid as the external orcontinuous phase may be subjected to the action of high tension electricfields to induce coalescence of the dispersed phase. By such treatmentwater-in-oil emulsions may be resolved, and typical examples of such useare the dehydration and desalting processes as applied-to crudepetroleum, whereby dispersed connate or added water is separated fromthe petroleum.

Separation as induced by this type of treatment normally involvescoalescence of the dispersed droplets under the action of the electricfield to form larger masses, and the separation of the coalesced massesby means dependent on the difference in density of the coalesced massesand the non-conducting external phase, such as gravitational settling.There are alsoactions of the electric field other than coalescence whichpromote separation. For example. ithas been found that particles of thesame size settle more rapidly ter treatment than before, possibly due totreating electrodes.

coalescence during settling and subsequent to the action of the electricfield. The degree or rate of coalescence or separation obtained is moreor less dependent on the voltage used, but the use of very high voltageshas hitherto been subject to the danger of short-circuiting by arcing orthe formation of conducting chains through the mixture being treated.

'It is an object of the present invention to provide an electricaltreater and method in which high voltages may be used without unduedanger of short-circuiting.

It is furthermore an object of the present invention to provide anelectric treater in which the emulsion to be treated may be introducedinto the treater through a grounded connection into a field generated bya substantially higher potential than exists between any of the liveelectrodes and ground.

I find that water-in-oil dispersions are best treated initially in ahorizontally extended field "between ,vertically spaced electrodes.

During or immediately following such treatment gravitational separation.begins to take place. In the case of oils lighter than water, thedispersed water particles following the initial electrical treatmenttend to settle downwardly, while the oil tends to rise. The oppositedirection of settling of course obtains if the oil is heavier, thanwater. In either case I find that it is advantageous to subjectthegravitationally separating streams, one or the other or both, to theaction of auxiliary or secondary electric fields prior to the completecoalescence of thestreams into a body of separated oil or a body ofseparated water as the case may be.

It is accordingly an object oi the invention to provide verticallyspaced electrode structures adapted to form auxiliary or secondarytreating fields in the regions in which the water and oil aregravitationally separating.

I find that it is particularly advantageous to subject the settlingwater particles to a field having its origin in a potential differencemaintained between the body of separated water and an electrode immersedin the as yet incompletely coalesced mixture, preferably one of the mainI find it convenient to maintain the body of separated water at zero orgrounded potential and to maintain the electrode cooperating with saidbody of water to form the secondary treating zone at a potentialsubstantially different from ground or zero potential.

It is accordingly an object of the present invention to provide anelectric treater having electrode means in which a secondary orauxiliary treating field is maintained between the body of separatedwater and an electrode comprised in said electrode means and situated inthe incompletely separated mixture.

I have furthermore found that it is advantageous to introduce theemulsion to be treated in a region intermediate the main verticallyspaced electrodes by means maintained at a potential intermediate thatof the electrodes so that the character of the gradient between theelectrodes is not materially or substantially changed by theinterposition of such emulsion introducing means.

It is accordingly an object of the present invention to provide a meansand method for the introduction of emulsion intermediate verticallyspaced electrodes maintained at difierent potentials at a potentialintermediate the potentials of the electrodes.

It is furthermore an object of the present invention to provide a novelelectrode structure comprising two pairs of vertically spaced electrodes with novel electrical and structural connections therebetween foruse in electric treaters of the type described.

bleed from the separator is objectionable, since the disposal of such"dirty or cloudy" bleed .water is troublesome and since, furthermore, an

actual loss in oil is thereby suffered.

It, is an object of the present invention to clarify the settled body ofwater obtained by electric resolution of emulsions, and to emovetherefrom entrained oil droplets.

It is furthermore an object of the present invention to provide meansand method for inducing currents in the settled body of water wherebythe water is swept free from oil and the oil returns to the zone of theauxiliary treating field.

It is furthermore an object of the present invention to provide meansand method for coalescing entrained .oil particles in the separatedwater, whereby the oil is massed into particles of sufilcient size tofloat or sinl; (depending on the relative density) from the water to theinterface. It is furthermore an object of the present invention toprovide means for such coalescence comprising means for mild agitationof the water, or for changing the temperature of the water, or forchanging the composition of the water, or for setting up directedcurrents in the water, or for introducing de-emulsifying orcoalescence-promoting chemicals to the water,

or for introducing material favoring coalescence by reason of itsphysical or chemical nature or the amount and direction of its momentum.

-It is furthermore an object of the present invention to provide meansand method for returning entrained oil to the interface, such meanscomprising means for introducing material such as water, or liquids withdensities not far removed from that of water, to the body of separatedwater in such manner that streams thereof move in the direction of theinterface in transporting or conveying relationship with entrained oil.Water which is substantially free of oil is preferred.

It is furthermore an object of the present invention to provide anelectric field resident in the oil phase or oil-continuous phaseadjacent the interface between the oil-continuous phase and the body ofseparated water, which field cooperates with the above mentionedsweeping, coalescing, or returning means, particularly by its eifectonoil droplets returned to the interface by the latter means, in promotingthe transfer of such oil droplets across the interface, and incoalescing the oil droplets with the body of oil. It is furthermore anobject of the invention to provide a field of the type described whichfacilitates the passage of both dispersed oil and water droplets acrosssuch an interfacial boundary into the phase continuous for the dropconcerned, and which in general tends to prevent the formation oraccumulation of coarse emulsions or cuffs at the interface. I

Further objects and aspects of my invention will be apparent in thefollowing part of the specification.

Referring to the drawing:

which feeds the emulsion into the electric field.

Fig. 4 is a sectional view of a spray head for the introducing of risingliquid masses into the body of separated water.

The details of one type of treater which I have found particularlyadvantageous are shown in Fig. 1. Referring to this figure, this treaterI0 provides a tank ll including a top member l2 and a bottom member Hi,this tank being grounded as indicated by the numeral [4.

Suspended from insulators I5 is a live electrode means shown asincluding an .upper live electrode l6 and a lower live electrode H, thelatter being supported from and electrically connected to the upper liveelectrode l6 by rods l8.

Suspended from an insulator 20 and positioned between the upper andlower liveelectrodes l6 and I1 is an intermediate live electrodestructure 2| cooperating respectively with the electrodes I6 and [1 inproviding an upper treating space 22 and a lower treating space 23. Iprefer to form the intermediate electrode structure 2| of two electrodes24 and 25 connected by a support 26.

The electrodes I6, I1, 24, and 25 are preferably interstitial incharacter. A form of construction which I have found particularlydesirable is illustrated in Figs. 1 and 2. Referring to the electrodel6, this electrode is shown as including a plurality of inner and outerrings 28 and 29 between which extend rods or pipes 30. Pins 32 dependtherefrom and carry a plurality of concentric rings 33 each of whichprovides a lower edge 34 adjacent which the electric field is veryconcentrated.

The electrode is similarly formed with rods or pipes 36 extendingoutward from a support 31 and carrying upward-extending pins which inturn mount a plurality of concentric rings 38. The rings 38 arepreferably disaligned from the rings 33 so that the most intense portionof any electric field established in the treating space 22 is inclinedas indicated by dotted lines 39 in Fig. 2. Suclran edge-to-edge field isvery eflective.

The electrode 25 is formed similarly to the electrode l6 and providesdownward-extending rings 45. Simi1arly,.the electrode I! is formedsimilarly to the electrode 24 and provides upward-extending rings 46 sothat a field is established in the treating space, 23 similar to thatpreviously described in the treating space 22, I have found itpreferable to form the electrodes l1 and 25 of smaller diameter than theelectrodes l6 and 24.

This type of electrode structure presents a minimum impedance togravitational separation in .the tank H, the rings and the supportingmeans therefor covering only a srnall'fraction of the totalcross-sectional area of the tank. Further, the interstitial nature ofthese electrodes permits free communication between the electric fieldsand facilitates rapid removal of coalesced water masses therefrom pVarious means may be utilized for energizing the electrodes to establishelectric fields in the treating spaces 22 and 23. All of theseelectrodes are live, the only grounded portions being the tank and theemulsifying distributor means 50, the latter discharging directly intothe treatlug space 23 to move the emulsion outward therein andsuccessively through the edge-to-edge fields. By proper design of theelectrical system, the potential between the intermediate electrodestructure 2i and the electrodes l5 and II can be made much higher thanthe potential between any of the live electrodes and ground. In Fig. 1such a system is shown as including two transformers 60 and Si connectedin additive relation. 'In this connection one terminal of each secondarywinding is grounded as indicated by the numeral 62, the high tensionterminal of the transformer 6! being connected by a conductor 63 to theintermediate electrode structure 2|, and the high tension terminal ofthe transformer 60 is connected by a conductor 64 to the upper and lowerlive electrodes l6 and I1. Suitable switches and control means limitingthe current to the primaries of these transformers may be utilized, suchmeans being well known in the art of electric dehydration .of emulsions.

Assuming; for instance, that each transformer develops a potential of12,000 volts, the potential across the upper treating space 22 will be24,000

volts, as will also the potential across the lower treating space 23.However, the potential between the emulsifying distributor means 50 andthe electrode 25, or the electrode II, will be only 12,000 volts; Use ofsuch a system tends to prevent short-circuiting to the emulsifyingdistributor means 50 and also permits introduction of the resultingmixture directly into a field of high voltage.

Under certain circumstances it may be desirable to introduce theemulsion at other than a grounded potential. Under these conditions, Istill prefer to control the potentialconcemed so thatthe potential ofthe introducing means is intermediate that of the two electrodes formingthe primary treating field, and preferably at a potential causing aslittle disturbance as possible to the gradient between the twotreatingelectrodes. By maintaining the emulsion introducing means at apotential at or near the potential corresponding to an unperturbed fieldpotential of the electrodes at the point or region occupied by theemulsion introducing means, I am able to maintain a maximum gradientthroughout the treating space with no danger of shorting due to highlocal gradients such as would occur in the neighborhood of an emulsionintroducing means maintained at a potential other than said intermediatepotential. Further advantages arise from the fact that the emulsionitself is introduced into the treating space at a potentialcorresponding to the unperturbed potential of the field whereby I find Iobtain more advantageous treating efiects.

I am not prepared to explain the exact theory of this effect, whichapparently involves not only the fact that the field is not perturbed,but also the fact that the emulsion is directly submitted the directionof settling, i. e., in a vertical direction. I

I may use various means for introducing the emulsion to the primarytreating field, although I find the emulsion distributor illustrated inFig. 3 gives excellent results. it will be noted that the pipe 5|carries a primary Referring to this figure,

member 52 which cooperates with a secondary member 53 in forming anannular discharge passage 54. It is often possible to movably mount thesecondary member 53, resiliently moving it toward the primary member 52so that the size of the annular discharge passage 54 is dependent uponthe quantity of the mixture moving through the pipe 5i. In accomplishingthis result, the secondary member 53 may be provided with a pin 55guided in a spider 5G and carrying a spacer 51 at its lower end. Acompression spring 58 is disposed between the spider 56 and the spacer51 and serves to resiliently move the secondary member 53 downward.-When no liquid is moving through thepipe 5i, the members 52 and 53 willbe in contact, but as soon as a flow is established, the pressure willforce the secondary member 53 upward a slight distance to open theannular discharge passage 54 in degree proportional to the quantity ofliquid to be discharged.

While satisfactory results, can sometimes be obtained by maintainingsubstantially atmospheric pressure in the treater i0, better resultshave been obtained by maintaining therein a pressure of.from five totwenty-dive pounds per square inch. Such a back pressure may be suitablymaintained by appropriate throttling of the draw-off valve [0| on thetreated oil line I00.

The action of the'electric fields is to coalesce or prepare forcoalescence the water particles of the mixture, which are thereby formedinto masses of suflicient size to gravitate from the oil.

Thus, after the treater has been in operation for The body of water willseparate at a rather;

definite surface or level indicated in Fig. l by the numeral 10. It isdesirable to control this 4 level to prevent grounding of the electrodel1 and to control the strength of the lower auxiliary treating field.For example, it will be apparent that an electric field will beestablished in an auxiliary treating space H between the lower liveelectrod I1 and the body of water in the bottom of the tank II. If thelevel 10 is carried too high, this auxiliary field may short out. If thelevel .10 is brought too low, the gradient through the field becomestoov low to afi'ord proper treating characteristics. With proper controlof the level 10, this auxiliary field can be utilized to further treatthe settling water particles and can b used to break an inversephase orreverse-phase emulsion, as will be hereinafter described.

To control the Water level in the tank II, I

have shown an automatic system including a pipe 15 communicating withtheupper part of.

the tank II and a pipev l6 communicating with a water draw-off pipe 11which opens on the lower end of the tank II. The pipes 15 and I6communicate with a fioat chamber 18 in which the oil and water are insurface contact at a level response to changes in the level I0. Thisfioat' may be pivoted on a pin connected to an arm 8| which is connectedto a valve 82 in the pipe 11 by any suitable means such as a link 83connected to an arm 84 of the valve 82 pivoted at 85 and operativelyconnected to the stem 88 of this valve. If the water level rises, thevalve 82 willthus be opened a further distance to drain additionalquantities of water from the tank Ii -and thus maintain the water levelconstant.

Various other systems for controlling the 'position of this water levelmay be utilized without departing from the spirit of the presentinvention.

I have found that in many instances there is a tendency for the settlingcoalesced water masses to carry downward therewith particles of oil.This is not conducive to a clean separation, and, if allowed tocontinue, will result in contaminated water bleeds, the oil beingcarried downward-into the body of water in the bottom of the tank. Ihave found that this action can be corrected by moving masses of waterupward through the body of water to sweep out any oil present andprevent downward movement of oil toward the water draw-off pipe 11.

A system which I have found very satisfactory in this regard isillustrated in Figs. 1 and 4. Disposed above and in protectingrelationship with the water draw-ofi pipe 11, I illustrate amultiorifice discharg head 90. This head may be formed of a cap 92, bestshown in Fig. 4, and provided with a plurality of orifices 93 formed todirect water upward and outward. Certain of these orifices may bevertically disposed, though best results are obtained if other orificesare angularly disposed relative to the horizontal. A plate 95 closes thecap 92 and receives a pipe 96 to which water is'delivered by a pipe 91.The incoming water is thus sprayed into the body of water in the lowerend of the tank II to form water masses which slowly rise toward thesurface due to the inclined nature of the orifices or to thermal actionor to a diiference in density if the incoming water is fresh, or, toVarious combinations of these factors. A desirable thermal effect isobtained by delivering to the pipe 91 water which is slightly hotterthan the water in the bottom of the tank H.- If desired, chemical agentsmay be delivered through pipe ill! to the stream of water flowing inpipe 91.

The action of these rising water masses is in part to sweep from thebody of water in the bottom of the tank ll any oil orreverse-phaseemulsion. ,The upward movement of the newly added water particles movessuch a reversephase emulsion toward the surfac 10 and thence into theauxiliary electricfield H in which such an emulsion is separated.

A number of effects actual-1y arise from the introduction of water asabove described or from the use of similar means, one of which is tocause a mild agitation of the separated water which is conducive tocoalescence of the dispersed oil droplets therein. Mild agitation suchas is atforded by the water spray or by other equivlent means forsetting up relatively slowly moving currents in the body of water,serves to increase the frequency of encounter between the dispersedparticles and is thereby conducive to coalescence and at the same timeis sufficiently mild to prevent any redispersion as by shearing anddisruption of oil particles. Following coalescence the oil droplets areof sufiicient size to gravitationally separate from the water, floatingor sinking, depending upon their density,

back to the interface between the separated water body and theoil-continuous phase.

I may also promote coalescence of the dispersed oil particles in theseparated water by changing the temperature of the water, for example byadding warmer water thereto, as illustrated. The effect 'of increasedtemperature is in general to decrease the stability of the films aroundthe oil droplets and thereby to promote coalescence.

in such a fashion as to decrease the stability of the dispersed oildroplets, and thereby induce coalescence. For example, as illustrated, Imay add fresh water to the body of more or less saline separated water,thereby decreasing the salt content of the latter. This is of particularadvantage where the dispersed oil droplets have been stabilized byadsorption of certain ions at the interface, for in such circumstancesthe dilution of the aqueous phase serves to remove or redissolve theadsorbed ions, and thus to decrease the stability of the dispersion andthereby to induce coalescence.

Under other circumstances, dependent to a large extent on the characterof the oil and water dispersion being treated, I find it advantageous tocause the adsorption of de-emulsifying agents at the interface, suchagents being of the type adapted to reduce the stability of thedispersion and to promote coalescence. I'may introduce such chemicalagents directly to the body of separated water, or I may add themthereto as aqueous solutions or dispersions, depending on theirsolubility, such solutions or dispersions, for example, beingconveniently added through a water spray of the type described foradding water to the separated body of coalesced water.

A large variety of chemicals are adapted to promote coalescence of theoil droplets as above described. For example, I may add salts,particularly polyvalent salts, which provide ions preferentiallyadsorbed at the interface and carrying a charge opposite to the chargeof the dispersed 'oil particles. Such salts may be even of the same typeas present in the naturally separated water, but which at a greaterconcentration serve to de-emulsify rather than stabilize the dispersionof oil in water.

.A wide variety of organic de-emulsif ying agents cal de-emulsifyingagent which is both oil soluble and water soluble. A convenient methodfor the introduction of such chemical de-emulsifying agents is to addthem by means of pipe I02 to the water flowing through the pipe 91,although various other means for introduction may be used, as indicatedabove.

In selecting a de-emulsifying agent for promoting coalescence, I find itis particularly advantageous to select an agent which is more or lessretained by the oil particle in its passage across the interfacialboundary to the oil-continuous phase and which will cooperate with theelectric field present in the region occupied by this phase in promotingamalgamation of the oil particle with the oil-continuous phase and ingeneral promote the electric treatability of the complex dispersedphases present in the neighborhood of the interfacial boundary, ashereinafter explained.

I have thus found various means for inducing coalescence of the oilparticles dispersed in the separated water which may be used separatelyor in combination.

My invention also provides a means for returning the oil particles, withor without prior coalescence, to the interface by inducing convoylng ortransporting currents in the body of water moving toward said interface.I find it particularly advantageous to provide such currents by theintroduction of a material of such;

density relative to the separated water that convection currents of thedesired transporting type are set up. I may also introduce streams orjets of material with an initially directed momentum which serve to setup the desired motion.

It is sometimes possible to dispense with the use of the secondarytreating field 22 as shown in Figs. 1 and 2, including both the upperand lower secondary electrodes. On the other hand, the auxiliarytreating field in the space H beaddition, various electrode structurescan be used with varying degrees of success, the embodiment illustratedbeing found particularly effective.

While the process'has been illustrated with particular reference to oilslighter than the. dispersed water, it is not essential that the oilbe oilower gravity than the water. If the converse is true, the principlesherein disclosed can be aptween the lower electrode and the separatedbody of water provides a number of advantages, such as a continuedtreating of the settling particles, and in particular I have found itadvantageous in its efiects on the interface in reducing or preventingthe formation of the fiocculent inter-- facial emulsions such as thepreviously mentioned sludge or cuff, and in promoting the transfer ofoil or water droplets across the interface and their subsequentcoalescence with the phase continuous in oil or water respectively.

Due to the complexnature of the interface, comprising as it normallydoes a region of transition from anoil-continuous phase to awatercontinuous phase with high concentrations of disperse phasesthroughout, and in many instances comprising polyphase emulsions aswell,

I am unable to present a precise theory as to the action of theauxiliaryfield on material at or near the interface. I find, however, that whenthe strength of this field is diminished, as when plied by withdrawnwater from the upper end of the treater tank, and'the hydrocarbonfromthe lower end, suitable changes in position of the insulators being madeto prevent short-circuiting of the electrodes. Such conditions may bemet in treating certain tars to remove water therefrom. This applicationis a continuation-in-part of my copending application Serial No.122,470, filed January 26, 1937, now patent No. 2,182,145, which is acontinuation-in-part of my copending application Serial No. 66,404,filed February 29,

I claim as my invention: v

1. A process for treating water-in-oil dispersions comprising:subjecting theidispersion to the action of a coalescing electric fieldand toa gravitational separating action, thereby causing the dispersedwater particles to settle from the treated dispersion; subjecting thesettling water particles'to the action of a second coalescing electricfield to further coalesce said settling the water level is allowed tofall too far away from the electrode cooperating therewith to form theauxiliary field, the quantity of oil in the bleed water increases, andaccumulation of sludge or coarse emulsion at the interface takes place,whereas when the field strength is properly maintained, as bymaintenanceof the water level at a higher point, the coarse emulsion is resolved orceases to form, and the bleed water is substantially free from entrainedoil. I find in general that an auxiliary field of sufficient magnitudeserves to promote cleaner separation at the interface, and alsocooperates with means for returning entrained oil to facilitate thepassage of the latter across the interface.

I find that the effect of the auxiliary field may frequently be enhancedby adding to the separated water certain chemicals which are in part atleast adsorbed or dissolved by the oil particles therein, so that thechemicals are brought to'the interface by the return of the oilparticles thereto. I find that various chemicals of this type serve toincrease the electric treatability of materials at or near theinterface, or material returned to the: interface. I have'obtainedexcellent results by using sulfonated fatty oil derivatives for thispurpose, and ingeneral I may use modified fatty acid derivatives,including the esters, and similar chemicals, such as are dis-' closed inPatent No. 1,467,831, issued to W. S. Barnickel, and in Patent No.1,829,205, issued to G. C. Walker.

As to the electric fields in general, alternating current fields arepreferred, either constantly water particles prior to their completecoalescence; maintaining a. body of separated water in which the furthercoalesced water particles completely coalesce adjacent the secondelectric field, said further coalesced particles tending to carryoil-droplets into said body of separated water; and introducing asubstantially oil-free aqueous mediumlnan upward direction into saidbody of separated water to sweep entrained oil droplets back toward thesecond electric field to bring the oil of said droplets into a zone ofinfluence of this field.

'2. A method of resolving a water-in-oil type of emulsion by treatingsame in' a chamber containing bodies of oil and water, which methodincludes the steps of continually introducing the emulsion to be treateddirectly into an oil-containing portion of said chamber and subjectingthis emulsion to the action of an electric field to coalesce at least aportion of the dispersed water into gravitationally separable masseswhich drop through the oil in said chamber to join said body of water,said body of water tending to become contaminated by dispersed oil.

- droplets; withdrawing water and oil from the occurring orintermittently applied, though the desired coalescence can take place ina unidirectional field of constant or pulsating potential. Fieldsresulting from the application of short electric surges to theelectrodes, or application of peaked potentials to the electrodes, canalso be used with success. Relatively high potentials are preferred, thepotentials and type of current being commensurate with those used in theart of electrically dehydrating emulsions. In

lower and upper ends of said chamber respectively; and clearing at leasta portion of the body of water adjacent the point of water withdrawal ofdispersed oil droplets by introducing into said body of water a hotsubstantially oil free aqueous medium which is at a temperature abovethe average temperature of said body of water, said medium being broughtinto direct contact with the body of water to establish .a thermalcircula tion in said body of water moving the oil droplets upward towardsaid electric field to bring the oil of said droplets into the zone ofinfluence of said field.

3. A method of resolving a water-in-oil type of emulsion by treatingsame in a chamber containing bodies of oil and water, which methodincludes the steps of: continually introducing the emulsion to betreateddirectly into an-oil-containing portion of said chamber and subjectingthis emulsion to the action of an electric field to coalesce at least aportion of the dispersed water into gravitationally separable masseswhich drop through the oil in said chamber to join said body of water,said body of water torming the lower terminus of said electric field;withdrawing water and oil from the lower and upper ends of said chamberat such rates as to maintain the amounts ofoil and water in said chambersubstantially constant from time to time and at such rates as to tend toform sludge in said chamber, whereby oil masses tend to pervade the bodyof water; and spraying water which is substantially oil free upward intosaid body of water to establish [an upward circulation in said body ofwater tending to move the oil masses therein upward to .bring the oilthereof into a zone of influence of the electric field immediatelythereabove for re-treatment.

4. A process for clarifying water separated i'rom a treated water-in-oildispersion resulting mm the subjection of an emulsion to a (malescingelectric field established adjacent an electrode, which process includesthe steps of: maintaining a body of separated water beneath thecoalescing electric field to receive the electrically coalesced watermasses settling from the oil, said water masses tending to carry oildroplets into said body of separated water; and claritying said water insaid body by spraying thereinto in an upward direction water which issubstantially free from oil in a manner to establish upwardly-risingcurrents in said body which droplets of oil into said separated body ofwater;

withdrawing water from said body of water at a point removed from saidinterracial zone; and

' clarifying said'body oi separated water to remove thereirom said oildroplets by discharg n directly thereinto water which is substantiallyoil free and which is of such density relative 'to the density 01' theseparated water as to. establish a circulation in said body of water tomove said oil droplets towards said body of oil and to bring the oil ofsaid droplets into a zone ofinfluence of said electric field.

7. A method of resolving water-in-oil type .emulsion by treating same-ina chamber containing a body oi. oil, a body of separated water, andaninterfacial zone representing the boundary between said body oi; oil andsaid body of separated water, which method includes the steps of:continually discharging the emulsion to be carry the oil droplets upwardtherewith-to bring Of said of separated water, which method includesthe,

steps of: continually discharging the emulsion to be treated directlyinto said body of oil in said chamber and there subjecting this emulsionto the action of an electric field of sufiicient intensity to coalesceat least a portion of the dispersed water into gravitationally separablemasses which gravitate from the body of oil in treated directly intosaid body of oil in said chamber and there subjecting this emulsion '66the action of an electric field of suflicient intensity to coalesce atleast a portion of the dispersed water into gravitationally separablemasses which gravitate from 'the body of oil in said' chamber to joinsaid body of water, said masses tending in their separation to carrysmall droplets of oil into said body of separated water; withdrawingwater from said body of water at a point removed from said interracialzone; and introducing a hot substantially ofl free aqueous medium intodirect contact with said body of separated water while atra temperatureabove the temperature of said body of separated water to clariiy'saidbody 01' water. and induce upward currents moving said droplets of oilupward whereby the oil-of said droplets is moved into a zone ofinfluence of said electric field.

8. A process as defined in claim 6, in which said body of separatedwater is brackish and in which. said water discharged directly thereintosaid chamber to join said body of ,water, said masses tending in theirseparation to carry small droplets of the oil into said body ofseparated water; withdrawing water from said body of water at a pointremoved from said interracial zone; and clarifying at least the portionoi' said body oi. separated water adjacent said point of withdrawal bydischarging substantially, oil free water into said body of water in adirection toward said interfacial zone to carry oil droplets toward saidinterfacial zone and subject the oil of said droplets to the action ofsaid electric field.

6. A method of resolving a water-in-oil type emulsion by treating, samein a chamber containing a body of oil, a body'of separated water,

' and an interfacial zone representing the boundary between said body'ofoil and said body of separated water, which method includes the betreated directly into,said body of oil in said chamber and theresubjecting this emulsion to the action of an .electriefield ofsuflicient intensity to coalesce at least a portion of the dispersedwater into gravitationally separable masses which gravitate from thebody of oil in said chamber to join said body of water, said massestending in their separation to carrysmall steps of:continually-discharging the emulsion to is less brackish so as to have adensity less than the water of said body, and in which said lessbrackish water is discharged into a zone of said body of water whichoccupies only a portion of the complete horizontal cross-sectional areaof said body of water at the point of discharge.

9. A method of resolving a water-in-oil type emulsion by treating samein a chamber containing a body of oil, a body of separated water, and aninterfacial zone representing the boundary between said body of oil andsaid body of separated-water, which method includes the steps ofcontinually discharging the emulsion to be treated directly into saidbody of oil in said chamber and there subjecting this emulsion to theaction of an electric field of suflicient intensity to coalesce at leasta portion of the dispersed water into gravitationally separable masseswhich gravitate from the body of oil in said chamber to join said bodyof water, said masses tending in their separation to carry smalldroplets of the oil into said body of separated water; withdrawing waterfrom said body of water at a point removed from said interracial zone;and discharging substantially oil free water carrying a chemicaldeemulsifying agent into said body of water to establish a circulationin said body of water away from said point of withdrawal and toward saidinterfacial zone and carry oil droplets and said chemical deemulsifyingagent toward said interfacial zone to bringthe oil of said oil dropletsI into a zone of influence of said electric field.

ing a body of oil, a body of separated water, and an interracial zonerepresenting the boundary between said oil-continuous body and said bodyof separated water, which method includes the steps of: continuallydischarging the emulsion to be treated directly into said body of oil insaid chamber and there subjecting this emulsion to the action of anelectric field of suflicient'intensity to coalesce at least a portion ofthe dispersed water into gravitationally separable masses whichgravitate from the body of oil in said chamber to join said body of'water, said masses tending in their separation to carry small dropletsof the oil into said body of separated water; withdrawing water fromsaid body of water at a point removed from said interfacial zone; anddischarging substantially oil free water into said body of water toestablish a circuing agent to said body of water to be carried by saidoil droplets toward and into said interiacial zone.

HAROLD C. EDDY.

